US9859774B2 - Linear actuator - Google Patents

Linear actuator Download PDF

Info

Publication number
US9859774B2
US9859774B2 US14/396,227 US201314396227A US9859774B2 US 9859774 B2 US9859774 B2 US 9859774B2 US 201314396227 A US201314396227 A US 201314396227A US 9859774 B2 US9859774 B2 US 9859774B2
Authority
US
United States
Prior art keywords
spindle
piezo element
linear actuator
bearing
piezo
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US14/396,227
Other languages
English (en)
Other versions
US20150115774A1 (en
Inventor
Norbert Klinke
Michael Lindekilde Randløv
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Linak AS
Original Assignee
Linak AS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Linak AS filed Critical Linak AS
Assigned to LINAK A/S reassignment LINAK A/S ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KLINKE, NORBERT, RANDLOV, MICHAEL LINDEKILDE
Assigned to LINAK A/S reassignment LINAK A/S ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KLINKE, NORBERT, RANDLOV, MICHAEL LINDEKILDE
Publication of US20150115774A1 publication Critical patent/US20150115774A1/en
Application granted granted Critical
Publication of US9859774B2 publication Critical patent/US9859774B2/en
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • H02K11/001—
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47B—TABLES; DESKS; OFFICE FURNITURE; CABINETS; DRAWERS; GENERAL DETAILS OF FURNITURE
    • A47B9/00—Tables with tops of variable height
    • A47B9/04—Tables with tops of variable height with vertical spindle
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/16—Measuring force or stress, in general using properties of piezoelectric devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
    • G01L5/0009—Force sensors associated with a bearing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
    • G01L5/0009—Force sensors associated with a bearing
    • G01L5/0019—Force sensors associated with a bearing by using strain gages, piezoelectric, piezo-resistive or other ohmic-resistance based sensors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
    • G01L5/0061—Force sensors associated with industrial machines or actuators
    • G01L5/0071—Specific indicating arrangements, e.g. of overload
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
    • H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/06—Means for converting reciprocating motion into rotary motion or vice versa

Definitions

  • the present invention relates to a linear actuator with a squeeze protection device based on a piezo element.
  • Linear actuators e.g. find application in adjustable furniture such as beds, resting chairs and height-adjustable work tables, where it would be critical, if a person was squeezed during the adjustment of furniture. Furthermore, it is unfortunate if the furniture inflicts damage to the surroundings and/or is damaged itself due to the fact that the adjustable element(s) of the furniture during the adjustment hits an infrangible object. As an example of the latter height-adjustable work tables also known as sit/stand tables, where the table top during the adjustment can hit a windowsill or a cable tray designed as a shelf for computer network cabling and/or electric cables.
  • FIG. 2 shows a drive unit comprising a driven chain running over two chain wheels. Each of the chain runs between the two chain wheels is equipped with a driving rod, which is displaced axially in opposite directions when the chain is moved. At the end of one of the two driving rods a squeeze protection device is mounted comprising a piezo element cf. FIGS. 3 and 4 .
  • a linear actuator is shown, where it is briefly mentioned that the piezo element can be placed in connection with a bearing for the spindle without it being specified how the piezo element should be arranged.
  • Linak A/S discloses a linear actuator with a special embodiment of a squeeze protection device, where a piezo element is surrounded by or embedded in an elastic material.
  • FIGS. 3-4 show an embodiment in the form of a linear actuator for lifting columns for height-adjustable work tables, where the motor as well as a piezo element is embedded in an elastic material.
  • FIGS. 5-6 show an embodiment in the form of a dual actuator for adjustable beds, where the elastic material with the piezo element is located in a small cavity in a wall construction constituting one side of a bearing bush for the bearing on the spindle.
  • the purpose of the invention is to provide a more concrete solution to the placement of a piezo element in connection with a bearing on a spindle and which further provides a satisfactory signal.
  • the solution according to the invention is as stated in claim 1 characteristic in that the piezo element has a through-going hole for the spindle.
  • the piezo element can have various geometrical shapes, e.g. square, hexagonal, octagonal, oval etc. It has, however, turned out that a ring-shaped piezo element is particularly expedient. In addition to being easy to mount it has also, not insignificantly, turned out that a particularly good signal/noise ratio is obtained.
  • the piezo element per se can be constituted by a piezo electric material, but in a particularly suitable embodiment the piezo element comprises a bearing part, on which there is a piezo electric material.
  • the bearing part can be a metal disc or ring, on which a layer of a piezo electric material is cast.
  • the piezo element is designed as a passive sound generator with a piezo element as a sensor, which is an inexpensive solution, but an active sound generator may of cause also be used, this solution is, however, more expensive.
  • the piezo element can be mounted in various ways e.g. retained by tongues in a recess or by means of glue, but is has turned out that it can be mounted in a very simple manner by means of double adhesive tape.
  • FIG. 1 shows a linear actuator in the shape of a lifting column
  • FIG. 2 shows a drive unit for the lifting column shown in FIG. 1 ,
  • FIG. 3 shows a spindle unit for the drive unit in FIG. 2 .
  • FIG. 4 shows a detailed view of the upper end of the spindle unit in FIG. 3 .
  • FIG. 5 shows a mounting plate from the upper end of the spindle unit in FIG. 4 equipped with a ring-shaped piezo element
  • FIG. 6 shows a detailed view of the upper end of the spindle unit equipped with a piezo element biased between the bearing and the mounting plate
  • FIG. 7 shows an exploded view of the piezo element and mounting plate
  • FIG. 8 shows an exploded view of the motor unit and housing of the drive unit
  • FIG. 9 shows a longitudinal section through a linear actuator.
  • FIG. 1 of the drawing shows a linear actuator in the form of a lifting column for height-adjustable (sit/stand) tables having three telescopic members 1 , 2 , 3 arranged inside each other, where the outermost member 1 with its lower end is intended for securing to a foot.
  • a housing 4 At the upper end of the innermost member 3 there is a housing 4 , which is located perpendicular to the broad side of the column.
  • the sides and the end of the housing, which are level with the members, are equipped with screw holes 5 for mounting the table top/frame carrying the table top.
  • FIG. 2 of the drawing shows the drive unit of the lifting column.
  • FIG. 3 shows the spindle unit of the drive unit in FIG. 2 .
  • the spindle unit comprises an outer tube 14 , the lower end of which is retained at the bottom of the outermost member 1 .
  • a coupler with internal threads for a hollow spindle 15 is secured, where the top likewise is equipped with a coupler with internal threads for a solid spindle 16 .
  • a bearing 17 is secured surrounded by a bearing bush 18 , cf.
  • FIG. 4 At the outermost end of the solid spindle 16 one part 19 a of a claw clutch is mounted intended for mesh with the other part 19 b of the claw clutch on a motor unit in the housing 4 .
  • the securing of the spindle unit to the housing 4 is carried out by means of a mounting plate 20 , which with two screws through screw holes 21 is screwed onto the bottom of the internal side of the housing 4 .
  • a mounting plate 20 which with two screws through screw holes 21 is screwed onto the bottom of the internal side of the housing 4 .
  • the upper end of the spindle unit extends through a hole in the bottom of the housing 4 .
  • the upper side of the mounting plate 20 is fitted with a piezo element 22 constituted by a bearing part in the shape of a metal ring ( 22 a ), on which a piezo electric material ( 22 b ) is cast.
  • a piezo electric material 22 b
  • the piezo element is mounted to the mounting plate 20 by means of double adhesive tape 22 c , see FIG. 7 .
  • the piezo element registers the bending of the mounting plate 20 as a result of the forces in the lifting column, as the forces are led through the spindle unit via the bearing 17 to the mounting plate 20 and from there to the housing 4 .
  • control device is laid out such that the power supply for the motor is cut off in case the piezo element registers a bending corresponding to a force of a given size, which typically originates from the table top hitting an obstacle.
  • the motor can possibly be brought to reverse before it is completely stopped in order for the table top to move a small distance away from the object it has hit.
  • FIG. 6 shows another embodiment, where the piezo element is biased in connection with the bearing 17 .
  • the hole in the mounting plate 20 is here punched and deep drawn, such that it appears with a ring-shaped wall 24 with an edge 25 , FIG. 4 .
  • the piezo element 22 is located between this edge 25 and the bearing 17 .
  • the forces are thus led directly from the bearing to the piezo element and from there to the mounting plate 20 .
  • the motor is stopped in that the power supply for the motor is cut off.
  • the motor unit 26 is located in the housing 4 .
  • the motor unit 26 comprises a reversible electric motor 27 and a transmission 28 in the form of a worm gear comprising a worm wheel 29 and a worm 30 .
  • the other part 19 b of the claw clutch is mounted on the worm wheel 29 of the worm gear, to be exact in a cavity of a cylindrical part on the side of the worm wheel.
  • FIG. 9 of the drawing shows a general-purpose linear actuator, e.g. for adjusting beds, resting chairs, machines, lifts etc.
  • the actuator has an electric motor 30 , which through a transmission, here a worm gear 31 , drives a spindle 32 with a spindle nut 33 .
  • An inner tube 34 surrounded by an outer tube 35 is secured to the spindle nut 33 .
  • a bearing 36 here a ball bearing, is secured to the rear end of the spindle 32 , said bearing having an outer ring and an inner ring, between which there is a number of balls.
  • the bearing 36 is located in a recess in a rear mounting 37 . To be exact the outer ring of the ball bearing 36 rests against a shoulder in the recess.
  • the compression forces on the inner tube 34 are thus transferred directly to the rear mounting 37 via the bearing 36 .
  • a ring-shaped piezo element 22 is located for registering the compression forces on the inner tube 34 .
  • the cable from the piezo element can relatively easy be guided in a groove intended for that purpose in the rear mounting and is guided to the control electronics for the actuator together with the other cables.
  • transmission 31 and rear mounting 37 is surrounded by a housing 38 .
  • the outer tube 35 is placed such that its rear end extends into an opening in the front end of the housing 38 .

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Transmission Devices (AREA)
US14/396,227 2012-04-23 2013-04-23 Linear actuator Active 2034-07-29 US9859774B2 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DKPA201200279 2012-04-23
DKPA201200279 2012-04-23
DK201200279 2012-04-23
PCT/DK2013/000031 WO2013159776A1 (fr) 2012-04-23 2013-04-23 Actionneur linéaire

Publications (2)

Publication Number Publication Date
US20150115774A1 US20150115774A1 (en) 2015-04-30
US9859774B2 true US9859774B2 (en) 2018-01-02

Family

ID=48536654

Family Applications (1)

Application Number Title Priority Date Filing Date
US14/396,227 Active 2034-07-29 US9859774B2 (en) 2012-04-23 2013-04-23 Linear actuator

Country Status (5)

Country Link
US (1) US9859774B2 (fr)
EP (1) EP2841897B1 (fr)
CN (1) CN104246461B (fr)
DK (1) DK2841897T3 (fr)
WO (1) WO2013159776A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180071035A1 (en) * 2015-04-21 2018-03-15 Cambridge Medical Robotics Ltd Load cells in an instrument drive
US20200085184A1 (en) * 2018-09-19 2020-03-19 Dong Guan Song Wei Electric Technology Co., Ltd. Adjustable table leg
US11662200B2 (en) 2018-04-18 2023-05-30 Logicdata Electronic & Software Entwiclungs Gmbh Sensor assembly, actuator, control system, electrically adjustable piece of furniture and method for operating an electrically adjustable piece of furniture

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USD826611S1 (en) * 2015-10-16 2018-08-28 Virco Mfg. Corporation Furniture leg attachment
DE202021103270U1 (de) 2021-06-17 2022-10-06 Veyhl Gmbh Höhenverstellbares Tischbein, Tischgestell und Tisch
DE102021206231A1 (de) 2021-06-17 2022-12-22 Veyhl Gmbh Höhenverstellbares Tischbein, Tischgestell und Tisch

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7049728B2 (en) * 2001-12-13 2006-05-23 Linak A/S Adjustable construction preferably an article of furniture and a squeeze protection and a drive unit thereto
DE202010015737U1 (de) 2009-11-26 2011-04-07 Linak A/S Linearantrieb und Möbelstück jeweils mit einer Vorrichtung zur Sperr- oder Klemmdetektion
US8539845B2 (en) * 2008-11-04 2013-09-24 Piezocryst Advanced Sensorics Gmbh Force-measuring ring having an annular housing
US20140000031A1 (en) * 2011-04-12 2014-01-02 Karsten Westermann Electric actuator system
US9016127B2 (en) * 2009-10-07 2015-04-28 Nec Tokin Corporation Piezoelectric acceleration sensor
US9155391B2 (en) * 2008-06-06 2015-10-13 Linak A/S Linear actuator

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101159418B (zh) * 2007-11-23 2011-05-11 清华大学 一种低压驱动的压电马达
RU2517023C2 (ru) * 2008-01-12 2014-05-27 Линак А/С Привод
JP5159697B2 (ja) * 2009-05-13 2013-03-06 曙ブレーキ工業株式会社 電動式ディスクブレーキ装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7049728B2 (en) * 2001-12-13 2006-05-23 Linak A/S Adjustable construction preferably an article of furniture and a squeeze protection and a drive unit thereto
US9155391B2 (en) * 2008-06-06 2015-10-13 Linak A/S Linear actuator
US8539845B2 (en) * 2008-11-04 2013-09-24 Piezocryst Advanced Sensorics Gmbh Force-measuring ring having an annular housing
US9016127B2 (en) * 2009-10-07 2015-04-28 Nec Tokin Corporation Piezoelectric acceleration sensor
DE202010015737U1 (de) 2009-11-26 2011-04-07 Linak A/S Linearantrieb und Möbelstück jeweils mit einer Vorrichtung zur Sperr- oder Klemmdetektion
US20140000031A1 (en) * 2011-04-12 2014-01-02 Karsten Westermann Electric actuator system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180071035A1 (en) * 2015-04-21 2018-03-15 Cambridge Medical Robotics Ltd Load cells in an instrument drive
US10653487B2 (en) * 2015-04-21 2020-05-19 Cmr Surgical Limited Load cells in an instrument drive
US11045266B2 (en) 2015-04-21 2021-06-29 Cmr Surgical Limited Load cells in an instrument drive
US11662200B2 (en) 2018-04-18 2023-05-30 Logicdata Electronic & Software Entwiclungs Gmbh Sensor assembly, actuator, control system, electrically adjustable piece of furniture and method for operating an electrically adjustable piece of furniture
US20200085184A1 (en) * 2018-09-19 2020-03-19 Dong Guan Song Wei Electric Technology Co., Ltd. Adjustable table leg
US10758036B2 (en) * 2018-09-19 2020-09-01 Dong Guan Song Wei Electric Technology Co., Ltd. Adjustable table leg

Also Published As

Publication number Publication date
CN104246461B (zh) 2017-03-01
EP2841897B1 (fr) 2021-12-15
EP2841897A1 (fr) 2015-03-04
WO2013159776A1 (fr) 2013-10-31
US20150115774A1 (en) 2015-04-30
CN104246461A (zh) 2014-12-24
DK2841897T3 (da) 2022-03-21

Similar Documents

Publication Publication Date Title
US9859774B2 (en) Linear actuator
US9480333B2 (en) Lifting column
US7049728B2 (en) Adjustable construction preferably an article of furniture and a squeeze protection and a drive unit thereto
EP3739239B1 (fr) Un actionneur pour convertir un mouvement rotatif en un mouvement linéaire alternatif
US9247806B2 (en) Lifting column preferably for height-adjustable tables
JP5236734B2 (ja) 治療台、病院用ベッド、および介護用ベッドのための昇降支柱
US8408083B2 (en) Linear actuator
US20110061570A1 (en) Linear actuator
WO2011063812A8 (fr) Colonne télescopique, de préférence pour meuble
US8794086B2 (en) Linear actuator and safety mechanism for the same
TWM499491U (zh) 電動推桿之結構改良
EP3148373A1 (fr) Cadre de support réglable en hauteur
US9327951B2 (en) Drive system for telescopic legs for tables
KR101894152B1 (ko) 전동침대
EP2498888A1 (fr) Jeu de construction comprenant un actionneur linéaire anti-surcharge
WO2009146709A3 (fr) Meuble réglable
US20220304462A1 (en) Actuator system and multifunctional table comprising such an actuator system
KR200470476Y1 (ko) 전동 테이블
JP6787698B2 (ja) 寝台装置
TWM656403U (zh) 具有保護機制的線性致動裝置
EP1686943A1 (fr) Lit d'hopital ou de soins
ITUB201552457U1 (it) Livellatore perfezionato
BRMU9102685U2 (pt) mesa com fuso de ajuste de subida e descida para procedimentos em animais domÉsticos.
SK5653Y1 (en) Lifting mechanism especially of the dental seat

Legal Events

Date Code Title Description
AS Assignment

Owner name: LINAK A/S, DENMARK

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KLINKE, NORBERT;RANDLOV, MICHAEL LINDEKILDE;REEL/FRAME:034066/0651

Effective date: 20140924

Owner name: LINAK A/S, DENMARK

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KLINKE, NORBERT;RANDLOV, MICHAEL LINDEKILDE;REEL/FRAME:034088/0403

Effective date: 20140924

STCF Information on status: patent grant

Free format text: PATENTED CASE

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 4